An Adult Zebrafish Model Reveals that Mucormycosis Induces Apoptosis of Infected Macrophages

Area of Science:

• Mycology
• Infectious Diseases
• Zebrafish Models

Background:

• Mucormycosis is a severe fungal infection with high mortality due to limited treatments and diagnostic challenges.
• The Mucorales order, particularly Rhizopus and Mucor species, are the primary causes of mucormycosis.
• Understanding the host-pathogen interaction is crucial for developing effective therapies.

Purpose of the Study:

• To develop and validate an adult zebrafish model for studying Mucor circinelloides infection.
• To investigate the relationship between sporangiospore size and fungal virulence.
• To elucidate the host immune response and identify novel virulence mechanisms in mucormycosis.

Main Methods:

• Infection of adult zebrafish with Mucor circinelloides sporangiospores.
• Transcriptomic analysis to study host gene expression changes.
• Histological examination and immune cell recruitment analysis (neutrophils and macrophages).

Main Results:

• The zebrafish model confirmed a correlation between sporangiospore size and virulence.
• Infection triggered a strong inflammatory response, involving cytokine and complement factor modulation.
• Mucormycosis induced apoptosis in recruited macrophages but not neutrophils, suggesting a key virulence strategy.

Conclusions:

• The adult zebrafish model is effective for studying mucormycosis pathogenesis.
• Macrophage apoptosis is identified as a critical virulence mechanism in mucormycosis.
• Targeting macrophage apoptosis presents a promising avenue for novel therapeutic interventions against this lethal infection.